1. Field of the Invention
This invention relates generally to a method and apparatus for transferring patient data recorded by a defibrillator during treatment of a patient. In particular, this invention relates to providing a recordable memory chip within the electrode connector. Electrotherapy devices include defibrillators, cardioverters and training devices that simulate the operation of an electrotherapy device. Defibrillators include automatic or semi-automatic external defibrillators (AEDs).
2. Description of the Prior Art
Electrotherapy devices are used to provide electric shocks to treat patients for a variety of heart arrhythmias. For example, external defibrillators typically provide relatively high-energy shocks to a patient (as compared to implantable defibrillators), usually through electrodes attached to the patient""s torso. External defibrillators are used to convert ventricular fibrillation or shockable tachycardia to a normal sinus rhythm. Similarly, external cardioverters can be used to provide paced shocks to convert atrial fibrillation to a more normal heart rhythm.
In 1991 the Advanced Cardiac Life Support Subcommittee of the American Heart Associate made a report to Health Professionals calling for increased access to defibrillation in order to improve the survival rates from sudden cardiac arrest (SCA). [Cummins, et al. xe2x80x9cImproving Survival From Sudden Cardiac Arrest: The xe2x80x98Chain of Survivalxe2x80x99 Conceptxe2x80x9d Circulation 83(5): 1832-1847 (1991).] The statistics themselves are staggering. On average 1000 adults die from SCA each day. Over 70% of these deaths occur in the home. Because the survival rate decreases 10% for every minute that passes, unless a defibrillator is available within the first few critical minutes, a victim of SCA has little chance of survival. If defibrillation were available, many of these people would survive. Following the AHA""s recommendations, there has been increased awareness of the importance of public access defibrillation and defibrillators have become increasingly available. [See, e.g., Newman, xe2x80x9cEarly Defibrillationxe2x80x94Making Waves Across America,xe2x80x9d JEMS Suppl. S4-S8 (January 1997).] The first phase of early defibrillation has been training designated lay responders in proper deployment of a defibrillator. Designated lay responders include, for example, fire fighters, police officers, flight attendants and security guards. However, with 70% of SCA occurring in the home, it becomes increasingly important to design a device that can be deployed by the average citizen in a home emergency.
One problem that could arise as defibrillators become ubiquitous relates to the ability to quickly and easily transfer patient data through the responder tiers. For example, a patient may initially be treated by a first responder carrying an AED. Information may be collected by the defibrillator relating to the patient ECG, shock decisions, etc. Thereafter a second tier responder, such as a paramedic, may arrive to provide treatment. At that time the second tier responder may wish to attach a defibrillator which provides additional functionality. Finally, the patient is transferred to a hospital. At some point it might be desirable to collected the data that was collected by each of the defibrillators in treating the patient to compose a continuous ECG readout. Where each piece of data is collected by a different machine and then correlated, errors could arise, for example, in the time correlation of the dataxe2x80x94for example where the clocks of the two devices are not set to the same base time.
What is needed is a method and apparatus for improving the data stream for a patient as he moves from a first tier responder to a second tier responder to a hospital. More specifically, what is needed is a way to provide data collection for the patient which is incorporated into an electrode connector.
An electrical medical electrode adapter is disclosed comprising: a housing, wherein at least one end of the housing forms a cable connector; an electrical conductor electrically connected to a socket within a shell of the cable connector; and memory disposed within the housing electrically connected to the electrical conductor. Typically the cable connector forms a male end which mates with a female housing end disposed on a defibrillator. In one embodiment, a pair of defibrillator electrodes electrically connected to the housing. Alternatively, a set of monitoring pads electrically connected to the housing. In its simplest form, a plurality of electrode pads are provided. That plurality includes from 2-12 electrodes; typically, three, five or twelve electrode pads. Where the medical electrode adapter is not formed integrally with the electrode pads, a female portion comprising an interior chamber is also provided which is adapted to receive a male medical electrode cable connector. In addition to memory, the adapter may include a clock. The clock would then be used to associate medical event data to be stored on the memory with time. Where a clock is provided a power source would also be provided. The capacity of the memory provided in the adapter should be sufficient to store 20 minutes of ECG sampled at 200 Hz; or approximately 500 kbytes.
A method of deploying a defibrillator is also provided comprising: turning the defibrillator on; attaching electrode pads to a patient; inserting a cable connector associated with the electrode pads into a housing for receiving the cable connector within the defibrillator; recording ECG data to a memory module associated with an electrode adapter associated with the electrode pads; removing the electrode adapter; and retrieving ECG data from the electrode adapter. Additionally, if an advanced tier responder arrives the additional step of disconnecting the electrode adapter from the first defibrillator and attaching the electrode adapter to a second defibrillator, wherein the electrode pads are still attached to the patient. Time data may be associated with patient ECG data using a clock on the electrode adapter associates or a clock associated with each of the defibrillators. In one embodiment, all ECG and event data relating to a medical emergency for a patient is recorded onto the memory. Alternatively, only a selected portion of the ECG data may be recorded. In this instance, optimally, a window of ECG data surrounding an event is recorded. An appropriate window of data is, for example, a twenty second window, i.e., twenty seconds before the event and twenty seconds after the event. Events for which a data window might be appropriate include: shock delivery, shock advised, no shock advised, and heart rate alarm.